Hi there. Sorry for all these questions. I must be the only person in the entire global English speaking TopSolid community needing the answers to such basic questions, either that or everyone else is too shy to ask. Anyhow -

When I installed TopSolid I was asked if I wanted to import libraries. I chose everything except for anything to do with Piping, Springs or IFC (see screenshot below).

QUESTION 1:
Could anyone tell me what each of these library groups are used for in TopSolid and why there is a need to install them?

Each of these libraries are specific. For example, TopSolid ANSI Mechanical includes standard mechanical components (screws, pins...) for the ANSI standard in inches. It is best to check in these libraries so that you can have access to them. But also know that some of the libraries require specific licenses to access. For example the ANSI, ISO, AFNOR CEN, and DIN libraries require a TopSolid Professional license to use.

TopSolid Mechanical includes references to basic items like tapping standards, filters, environments and so on. This is available for all licenses.

Everything that has Machining or Machine in its title has to do with TopSolid'Cam and is required if you are a TS Cam user.